Within the framework of a Modified Poisson-Boltzmann theory accounting for
steric effects of microions, we prove analytically that the effective pair
interactions between like-charge colloids immersed in a confined electrolyte
are repulsive. Our approach encompasses and extends previously known results to
the case of complete confinement, and further incorporates the finite size of
the microions which is absent in the standard Poisson-Boltzmann theory.Comment: 5 pages, 1 figure, to appear in Physical Review